1. Field of the Invention
This invention relates to a cable reel which may be used in conjunction with a cradle and a handset, such as a telephone handset or remote control for electronic apparatus, such as is typically but not exclusively used in various modes of mass transport including aircraft, vessels, rail and road passenger vehicles. Such handsets and cradles may also be used to facilitate audience participation or interaction in theatres, arenas, lecture theatres, libraries and similar locations.
2. Description of the Related Art
It is known to provide a cradle in the armrest of a chair, such as a seat in an aircraft, for housing a handset comprising, for example, a telephone and/or a remote controller for inflight entertainment apparatus. Such handsets can also include call functions for the in-flight staff. A typical example is the model RU-AA6501-01 of Matsushita Electrical Industrial Company Limited of Osaka, Japan. Similar handsets and cradles may also be mounted in other locations such as in or on aircraft bulkheads or seat backs: see for example U.S. Pat. Nos. 5,128,993, 5,410,597 and 5,155,766.
Conventionally such cradles comprise a recess in which the handset is stowed and from which the handset can be removed for example by lifting. The handset is electrically powered and collected via a cable which is housed in and may be drawn from a cable reel as the handset is removed from the cradle. As the handset is stowed, the cable is rewound into the reel under spring action, so as to leave no potentially hazardous freely exposed cable loop. To simplify cradle installation as well as helping to ensure proper retraction of the cable, the reel may be housed in or mounted on the cradle, with the cable routed directly from the reel into the recess. Alternatively the cable reel may be mounted separately from the cradle with a cable run or guide extending therebetween (see for example U.S. Pat. No. 5,109,412 and International patent publication no. WO 95/29552).
With repeated use of the handset, the cable is prone to wear. The cable or reel are often provided with a releasable locking mechanism to relieve the spring tension on the extended cable and prevent this tension from being experienced by the user. The locking mechanism is likewise prone to wear and damage in use. Prior art cable reels are not readily serviced or repaired "on site", i.e. at the location (aircraft, vehicle, building etc) in which they are used. A particular difficulty arises because the handset cable is wound/unwound from a rotatable spool and connected to a ribbon cable coiled within the cable reel to provide an electrical connection between the moving handset cable and a stationary connector on the reel casing. The spool, handset cable and ribbon cable cannot be readily dismantled and reassembled without the use of specialist tools and off-site facilities.
To simplify manufacture, a prior art cable reel developed by the present applicants has a spool comprising a pair of flanges defining between them a circumferential groove from which the handset cable is wound and unwound, a central, axially extending recess in which the ribbon cable is housed, and a notch in one of the flanges into which the handset cable and an attached ribbon cable can be simply laid so as to pass from the groove into the recess without the need to thread the cables through the spool in a direction along the cable axes, or the need to subsequently make up a connection between the ribbon cable and the handset cable. However these prior cable reels are manufactured as sealed units, either as a discrete unit for use with a separate handset cradle, or integrated with a handset cradle which forms a sealed housing for the reel. In either case, on site servicing of the cable reel is not practicable. Once the cable or other internal components of the reel become worn or damaged the entire reel or cradle assembly must be discarded.
It is an object of the present invention to provide a cable reel which may be readily serviced on site without the need for special tools or equipment.
It is a further object of the invention to provide a cable reel having cable components which may readily be replaced without the use of special tools or equipment.
It is a further preferred object of the invention to provide a cable reel having a mechanism for locking the cable in an extended position against a retraction spring force, in which the mechanism is accessible for servicing or repair.